Increasing antimicrobial resistance among Shigella isolates in the Bushehr, Iran.

Antibiotics are drugs used for treatment of infections caused by bacteria. Misuse and overuse of these drugs have contributed to phenomena known as antibiotic resistance. In this research, the antimicrobial resistance of the Shigella has been determined. This descriptive research analyzed registered laboratory data of patients referred to Fatemeh Zahra Hospital of the Bushehr, Iran. Shigella was isolated from their cultured sample from the year 2002-2008. In this study, the total of 121 registered Shigella collected from 2002-2008 were analyzed. There were 62 cases of S. sonnei, 46 cases of S. flexneri, eight cases of S. boydii and five cases of S. dysenteriae among them. Furthermore, two cases of Shigella sonnei were collected from the blood and the rest from the watery stools of the infected patients. The following is the resistance pattern of these organisms; to ciprofloxacin, 4.25%; ceftizoxime, 8.62%; nalidixic acid, 12.12%; co-trimoxazole, 86.13% and to tetracycline, 93.02%. Results ofantibiogram showed that highest rate of drug resistance belongs to tetracycline and co-trimoxazole and the lowest belongs to ciprofloxacin and ceftizoxime. One of the important issue for clinicians, now a day is drug resistance of microorganisms. This phenomenon is increasing due to some factors such as improper use of antibiotics and irrational prescribing. These factors lead to development of new drug resistant species.